I was told that with saulosi, acei and rusties that m:f ratio wasn't as imperative as other species.
I'd say there are vary degrees of certainty to that statement depending on the species. Aceis you're right m:f doesn't typically matter in a group of say 6, 3m:3f would probably work or possibly more males than females. But in a 4' tank, I wouldn't want 6 aceis, and with fewer fish to spread even the aceis tiny bit of aggression, it'd be safest to have only 1 male.
Saulosi, I think ratio matters. I think its usually recommended 1m:3f or 3m:9f. The 1m:3f recommendation was assuming you wanted to try 5 species, I didn't think there'd be room for a colony with 3 male saulosi.
With rusties, I'd probably recommend 1 male per tank. I have 4 males and 4 females. They've matured and started breeding. Lots of chasing, no deaths. I removed 3 males a month ago, and the male I kept keeps his 4 girls so busy that I'm thinking about adding a couple more females. The other 3 males have been living alone in a 33XL until I find someone who will take them from me, and they havent killed each other yet, but they're clearly not happy, and they do a lot of chasing each other. They've been in there for a month. 1 is colored nicely but not as nicely as my dominant male in my 125. The second is half colored, and the 3rd is completely brown like a female.
If you guys were stocking this tank...which would you choose the maingano or the albino scolofi? I definately want the acei and saulosi and the rustie (acei and rustie have purple, saulosi and acei yellow, so they color coordinate) If I have to choose only 4 species I am leaning towards maingano to bring out blue in acei and saulosi males...
This is just personal opinion, but I like the maingano looks better. I have some albino zebras that are similar looking to albino socs, and I'm just not at all interested in them. Mine don't have much personality, they haven't exhibited any interesting behavior, and they've been causing me the most trouble in the tank - 1 male was killed recently, and another was removed to an isolation for recovery from stress until recently returned to the display to make room for fry. I'm swapping them out for something else more interesting within the next couple months. I thought they'd make a nice color contrast to the rest of my tank, but TBH the novelty wears off pretty quickly.
Maingano made my short list as a swap in. I tried them once before and had to get rid of them because I just wasn't having any luck with them - ended up with 4m and 2f, the initial dominant male was killed by a smaller male that became a huge psycho at 2", and 1 of my females was just about chased right out of the tank relentlessly by all the other mainganos, including the other female. So I was soon to be left with 3m and 1f... So I just got rid of them all. Now with a bigger tank and more experience I feel I could try again and get it right.
But, I'll hopefully end up with fuelliborni marmalade as the replacement, though I wouldn't recommend them for a 4' tank. For your tank, I'd try the maingano over the albino socolofi. But again, its a personal opinion.